Domestic waste materials represent a continuing and growing disposal problem due to urban growth and lack of suitable land fill sites. Collection and transportation of domestic wastes from individual and multi-unit dwellings involves a considerable expense. Attempts have been made to incinerate such wastes to remove the combustible and putrescible content and in order to decrease the land fill requirements of the resulting ash. Such incineration procedures have involved the use of large excesses of air in the combustion, have involved the discharge of high temperature flue gases to atmosphere and have resulted in the discharge of high levels of pollutants, particularly particulate solids.
Further, domestic solid wastes usually contain a high proportion of food and other putrescible wastes, which dictate the establishment of land-fill sites remote from habitation, increasing further the expense of transportation.
Additionally, domestic wastes typically have an appreciable calorific value, generally in excess of 4,000 BTU/lb., due to the large proportion of combustible material present in the wastes, and hence the disposal thereof as land fill or the incineration thereof with discharge of the resulting flue gas represent a loss of a potential energy source.
There have been attempts to recover energy from solid wastes but such attempts generally have been confined to the generation of steam for in-plant use or for sale. Such steam generators, however, are quite sophisticated and, hence, expensive. Further, such generators must have markets for the steam they produce in order to be effective in resource recovery.
As far as we are aware, no attempts have been made to provide an on-site waste disposal system for a concentrated population housing development, such as, an apartment building, a townhouse development or a self-contained housing subdivision, which utilizes the calorific value of the waste material.